Lesson Simple Machines and Modern Day Engineering Analogies

Learning Objectives

After this lesson, students should be able to:

• Describe the engineering design process.
• Recount the uses and advantages of each of the six types of simple machines.
• Demonstrate a basic understanding of the methods in which simple machines may be combined to make complex machines.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

International Technology and Engineering Educators Association - Technology

Worksheets and Attachments

Pre-Req Knowledge

General understanding of pyramids. An understanding of the six simple machines, their various uses and how they may be combined to form complex machines, which may be accomplished by completing Lessons 1-5 (and associated activities) of the Simple Machines unit. Ability to work constructively in teams, including brainstorming and design work.

Introduction/Motivation

Welcome to modern day engineering. You have just completed building a new pyramid for the ancient Egyptian leaders. The pyramid looks great and they are pleased with your work. Through the design and construction of the pyramid, you learned a lot about what engineers do and what they use, from the engineering design process to the use of simple machines. Without using simple machines, building the pyramids would have been extremely difficult, if not impossible. But by using what you learned, you were able to do it. Congratulations!

Now that you are back to the present, I want you to see how what you learned and did to make the ancient pyramid is similar to what is used to make gigantic, modern buildings. In the thousands of years since ancient Egyptian times, technologies have developed and materials have improved, but you should recognize the simple machines from our previous activities and see how they are used today.

Upon hearing about your success in ancient Egypt, the CEO of a local corporation hired your engineering team to design and make a new building. She trusts you entirely with the project. She has not specified the type of building or its purpose, so you can build whatever you want. Her only criteria are that the building be massive to provide space for her large number of employees, that it serve a purpose that benefits people in the community, and that its design and construction be a reasonable cost and efficiency to serve its purpose (don't waste space!).

Who remembers why, historically, people have used machines? To make things easier, of course! Thousands of years ago, there were no automobiles or big cranes or screwdrivers. So, to construct projects of any magnitude, from a tiny shelter to a giant pyramid, certain machines were used to help make the life of the builder easier. Today, we call these contraptions simple machines, and they provide us with a mechanical advantage.

In ancient Egypt, the use of simple machines became widespread (we think!), as a result of one of the most impressive constructions in human history — the building the Pyramids at Gizeh. Without simple machines, the pyramids would have been impossible to accomplish. The sheer amount of work required to lift the giant stones would have been far too much to do without machines to make it easier. Remember, some stones in the pyramids weighed as much as 18,000 kilograms (or 20 tons or 40,000 pounds)! Can you imagine having to lift one of those, even with 100 of your strongest friends helping?

Let's think about simple machines a bit more. What are the six simple machines? (Answer: Wedge, wheel and axle, lever, inclined plane, screw, pulley.) How, historically, have simple machines been used by engineers in construction? (Possible answers: To build pyramids, castles, cathedrals, shelters, bridges, any non-modern structure.) Can simple machines be used together to solve problems? How? (Answer: Yes. Look for any sensible combination of machines; encourage creative answers and more questions.) How might an engineer go about designing a new structure? What might be the steps? (Answer: Write on the board the main steps in the engineering design process, and discuss with the students. Steps: Understand the need, brainstorm, design, plan, create, improve.)

In case you do not remember just exactly what simple machines do, and what they are, we have a short review to help us all refresh our memories. (Show the Review of Simple Machines, a PowerPoint presentation, or print out the slides to use with an overhead projector. The presentation is animated to promote an inquiry-based style; each click reveals a new point about each machine; have students suggest characteristics and examples before you reveal them.)

After the presentation, we will all have a good idea about why we use simple machines, and we can start thinking about how we might use simple machines to help us become engineers who design and build modern structures.

Lesson Background and Concepts for Teachers

Use the attached Review of Simple Machines PowerPoint presentation as a helpful classroom tool.

This lesson serves as the final lesson for the Simple Machines unit, providing students with an opportunity to apply the simple machines concepts they have learned in the previous five lessons in a design/build situation. Or, this lesson is suitable as an independent lesson for students who have a basic understanding of the six simple machines.

In the activity, students perform as engineering teams given an assignment to choose a type of structure to build, and use simple machines in different ways to construct that structure. Students see that teamwork is important in engineering, and that today's most impressive structures rely upon ancient technologies — the six simple machines.

The most important lesson goals are teamwork, creativity, problem solving using tools like simple machines, and learning the engineering design process. Challenge students to work cooperatively in teams, brainstorming and making design decisions based on group consensus.

Simple Machines

Throughout history, engineers (and people, in general) have searched for ways to make their lives easier. If a machine can be made to do or lessen the work usually required by a single person or group of people, then that machine is beneficial to the entire engineering process. In turn, new designs can be created as a result of these machines, with a greater ease of construction in mind. Thousands of years ago, these technologies took the form of the six simple machines — the wedge, wheel and axle, lever, inclined plane, screw, and pulley. Combining simple machines to form complex machines is an integral part of any manufacturing process. Even simple hand tools are either simple (for instance a hammer is a lever, and a saw is a wedge) or compound machines (an axe is a wedge at the end of a lever!). Complex fabrication machines such as lathes and mills are easily broken down into their composite parts — a wheel and axle attached to a pulley system, driven by a screw! A drill bit used in a lathe or mill, is a combination of a screw and a wedge. Modern-day buildings require that engineers use updated versions of simple machines and compound machines to solve problems analogous to their use in ancient Egypt. Where, in ancient times, moving heavy objects was assisted with simple pulleys, today, huge cranes (complex systems of pulleys and levers) lift even the heaviest of objects.

Simple machines are basic components of more complex systems that serve a simple purpose: to decrease the amount of work a laborer must do. This work savings is the result of a concept called mechanical advantage, which results when one trades the easing a task for taking a little longer to complete the task. For example, if you take the stairs instead of a ladder, you still get up to the next floor, but the stairs are easier to take — they just take a little more travel distance.

Each simple machine serves a unique purpose, and may be used in a wide range of applications. See the Review of Simple Machines PowerPoint presentation, for a good review (for students or teacher) of the functions of simple machines, as well as short descriptions, diagrams and examples. Simple machines become especially useful when used in concert with one another, in what is called a compound or complex machine. Most modern-day machines are compound, though simple machines can still be found in hand tools, for instance a screwdriver is a type of lever and a chisel is a type of wedge.

Engineering Design Process

Engineers design and build all types of structures, systems and products that are important in our everyday lives. The engineering design process is a series of steps that engineering teams use to guide them as they solve problems:

1. Ask: Identify the Needs and Constraints: What is the problem? What do I want to do? What are the project requirements? What are the limitations? Who is the customer? What is the goal?
2. Research the Problem: Gather information and research what others have done. Talk to people from many different backgrounds and specialties to assist with researching what products or solutions already exist, or what technologies might be adaptable to your needs.
3. Imagine: Develop Possible Solutions: You work with a team to brainstorm ideas and develop as many solutions as possible. This is the time to encourage wild ideas and defer judgment! Build on the ideas of others! Stay focused on topic, and have one conversation at a time! Remember: good design is all about teamwork!
4. Plan: Select a Promising Idea: Revisit the needs, constraints and research from the earlier steps, compare your best ideas, select one solution and make a plan to move forward with it.
5. Create: Build a Prototype: Building a prototype makes your ideas real! These early versions of the design solution help your team verify whether the design meets the original challenge objectives. Push yourself for creativity, imagination and excellence in design.
6. Test and Evaluate Prototype: Does it work? Does it solve the need? Communicate the results and get feedback. Analyze and talk about what works, what doesn't and what could be improved.
7. Improve: Redesign as Needed: Discuss how you could improve your solution. Make revisions. Draw new designs. Iterate your design to make your product the best it can be.
   And now, REPEAT!

Engineers use their science and math knowledge to explore all possible options and compare many design ideas. This is called open-ended design because when you start to solve a problem, you don't know what the best solution will be to meet the requirements. The process is cyclical and may begin at, and return to, any step.

The use of prototypes, or early versions of the design (or a model or mock-up) helps the design process by improving the understanding of the problem, identifying missing requirements, evaluating design objectives and product features, and getting feedback from others.

Engineers select the solution that best uses the available resources and best meets the project's requirements. They consider many factors before they implement a design: Cost to make and use, quality, reliability, safety, functionality, ease of use, aesthetics, ethics, social impact, maintainability, testability, ease/cost of construction and manufacturability.

Using the Engineering Design Process in this Lesson

In this lesson and its associated activity Modern Day Pyramids, students discover that the design process begins with a brainstorming session that provides multiple creative ideas to solve a problem. Next, the best brainstorming idea(s) are refined and developed, and assessed to determine if they are viable in the context of the problem. Finally, once all of the options have been examined, the engineering team chooses the idea they feel is the best solution, and the implementation process begins.

Two key themes of the engineering design process are teamwork and design. Since students are working in small groups, encourage them to think about the steps of the engineering design process. How will they work well together, listening to and respecting all ideas in the brainstorming session, reserving any judgment until a decision is made? Even then, make the decision-making process as democratic as possible, with all opinions being heard. Once a teamwork base is established, build upon that with a creative design. If a team of students is excited about their idea, they can come up with some fun methods for improving or extending the original idea. Reinforce with them that the end goal is a final design solution that is a seamless blend of creativity and utility. The implementation of the students' design (in this case the realistic uses of simple machines and complex machines) is something that can be considered as well.

Associated Activities

• Modern Day Pyramids - Students investigate the ways in which ancient technologies — six types of simple machines and combinations — are used to construct modern buildings. As they work together to solve a design problem (designing and building a modern structure), they brainstorm ideas, decide on a design, and submit it to a design review before acquiring materials to create it (in this case, a mural depicting the design). Emphasis is placed on cooperative, creative teamwork and the steps of the engineering design process.

Lesson Closure

One of an engineer's biggest jobs is to improve people's lives by making them easier. Using their knowledge, they design buildings, bridges, equipment, machines, tools and many other things to benefit people. Once engineers determine a design, they use whatever they can, such as simple machines, to make the construction or manufacturing process easier. Without using simple machines, the enormous projects they create would be impossible, or at the very least, cost more and take longer.

Who remembers what mechanical advantage is? It is the fact that simple machines can provide us with a trade-off; they trade ease of work with distance or time. For instance, climbing straight up from one floor to a higher one is a short distance, but stairs (a version of an inclined plane) make it much easier to climb, though the distance taken is longer. Simple machines all give a mechanical advantage — making work easier.

Engineers are problem solvers. Sometimes they solve existing problems, and other times they think up problems or difficulties and then solve them. Problem solving is an important skill that engineers work to develop. Engineers must be very creative to be able to problem solve well.

Engineers always work with other people to generate good ideas that they might not have thought of alone and to share tasks. This is called teamwork. Without the help of others, massive projects may never be completed, even if they used a lot of simple machines. Teamwork is important in problem solving.

Engineers are also inventors. If they need something that does not exist yet, they create it. Engineers from thousands of years ago would probably be surprised to see the machines and devices that we use everyday, such as computers and airplanes. How did these things, which people thought were impossible, eventually come into being? The answer is that ideas build upon each other. People take the work that one person has done and develop it a step further. Remember the simple machines used in ancient times and think about how they evolved into the powerful, modern tools used today. What will be the next tools that will be developed? Things often develop one step at a time with the focus on how to improve what is already there. Is there something that people might say is impossible now that may be developed in the future?

Engineers need teamwork, creativity, problem solving using tools like simple machines, and the steps of the engineering design process to be successful. The engineering design process helps engineers organize their problem to solve and creatively complete it with the available time and money.

(optional: Show students the What Is Engineering? video)

Use the attached Modern Day Pyramids Worksheet to reinforce student learning of the concepts.

Conduct summary assessment activities as described in the Assessment section.

Vocabulary/Definitions

compound machine: A combination of one or more simple machines used to cooperatively utilize their characteristic applications.

creativity: Characterized by being imaginative, original and expressive.

design: (verb) To plan out in systematic, often graphic form. To create for a particular purpose or effect. Design a building. (noun) A well thought-out plan.

engineering: Applying scientific and mathematical principles to practical ends such as the design, manufacture and operation of efficient and economical structures, machines, processes and systems.

engineering design: The process of devising a system, component or process to meet desired needs. (Source: Accreditation Board for Engineering and Technology, Inc.)

engineering design process: A decision-making process used by engineers. Combines an understanding of basic sciences, mathematics and engineering sciences to use available resources (material, people) to meet a desired goal, usually resulting in a product or system. (Source: The Design Process, Micron Technology, Inc., http://www.micron.com/students/engineer/design.html)

force: A push or pull on an object.

inventor: A person who is the first to think of or make something.

mechanical advantage: An advantage gained by using simple machines to accomplish work with less effort. Making the task easier (which means it requires less force), but may require more time or room to work (more distance, rope, etc.). For example, applying a smaller force over a longer distance to achieve the same effect as applying a large force over a small distance. The ratio of the output force exerted by a machine to the input force applied to it.

problem solver: A thinker who focuses on a problem, and combines information and knowledge to find a solution.

simple machine: A machine with few or no moving parts that is used to make work easier (provides a mechanical advantage). For example, a wedge, wheel and axle, lever, inclined plane, screw, or pulley.

teamwork: Cooperative effort by the members of a group to achieve a common goal.

work: Force on an object multiplied by the distance it moves. W = F x d (force multiplied by distance).

Assessment

The entire lesson, and its activity, serves as an assessment tool for students who completed the previous five lessons of the Simple Machines unit or who are already familiar with the six simple machines.

Pre-Lesson Assessment

Discussion & Questions: Lead a class discussion to determine how much the students know about the six types of simple machines, refresh their memories concerning previous simple machine lessons and activities, and plant the idea of the engineering design process. Use the Review of Simple Machines PowerPoint presentation, to help students visualize the machines, and guide the discussion. Solicit, integrate and summarize student responses. Ask the students:

• What are the six types of simple machines? (Answer: Wedge, wheel and axle, lever, inclined plane, screw, pulley.)
• How does each simple machine work?
• What are some everyday examples of each type of simple machine? (list on the board)

Post-Introduction Assessment

Discussion: Continue the class discussion from earlier with the following thinking questions. Solicit, integrate and summarize student responses. Ask the students:

• How, historically, have simple machines been used by engineers in construction? (Possible answers: Pyramids, castles, cathedrals, shelters, bridges, any non-modern structure.)
• Can simple machines be used together to solve problems? How? (Answer: Yes. Look for any sensible combination of machines; encourage creative answers and more questions. See examples in the Review of Simple Machines PowerPoint presentation.)
• How might you go about designing a new structure? What might be the steps? (Answer: Engineering design process steps: Understand the need, brainstorm, design, plan, create, improve.)

Engineering Design Loop: Divide the class into six or more teams. Have each team take a different step of the engineering design loop and create a drawing or explanation of the step on a letter-size piece of white or construction paper. Have each student team explain their step to the rest of the class. Hang the steps in a circle someplace in the classroom where they can be seen and referred to in the following order and circling clockwise: Understand the need (at the top), brainstorm, design, plan, create, and improve. Ask the students if the design process always moves in a clockwise direction? (Answer: No. The loop can go clockwise or counterclockwise. It goes counter clockwise when an engineer has a product and is trying to imitate it. Also, the design loop can jump around if you create and then need to go back to brainstorm again.)

Lesson Summary Assessment

ABCs: A fun and effective summary assessment, and one that requires a good amount of thought, is asking students to find a word about the lesson and activity that corresponds to each letter of the alphabet. For instance: A = Advantage, B = Building, C = Cooperation, etc. Continue down the list, having the students address each letter. If they get stuck, skip that letter and later, use a dictionary or make it an overnight assignment. Even though letters like X or Z are always challenging, that is the best part of this assessment as students are really required to think it through to come up with a particularly difficult word. The more connections made, the more different ways a memory is used, the more easily it is recalled later!

Recap Questions: As a class, ask students to review with you the steps in the engineering design process. (Answers: Understand the need, brainstorm and design, plan, create, improve. See details in the Lesson Background and Concepts for Teachers section.)

Worksheet: Have the students complete the activity worksheet; review their answers to gauge their mastery of the subject.

Engineering Design Practice: Have the students practice explaining the steps of the engineering design loop (Understand the need, brainstorm, design, plan, create, improve) with the following real-world scenarios:

• Make a peanut butter and jelly sandwich.
• Build a foot bridge across a river.
• Build a device to keep a brother or sister out of your bedroom.

Lesson Extension Activities

Conduct a classroom project involving "Rube Goldberg machines." Rube Goldberg (1883-1970) was an American engineer and cartoonist who is remembered for his "Rube Goldberg machines," devices that are exceedingly complex yet perform very simple tasks. Rube Goldberg machines are a series of simple machines linked together, often to perform mundane tasks, like toasting bread or cooking eggs, in a very indirect and convoluted way. The best examples of his machines are suspenseful (take a while to happen), wacky and fun. Students can really explore the uses of simple machines in fun, unorthodox methods. See the Official Rube Goldberg Website at http://www.rubegoldberg.com/.

Have students research the construction methods of structures not discussed in the lesson, for example a bridge, pier or work of art such as the statue of liberty or the Eiffel Tower.

References

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Acknowledgements

The contents of these digital library curricula were developed by the Integrated Teaching and Learning Program under National Science Foundation GK-12 grant no. 0338326. However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government.